Motor controller



May 29, 1928.

W. O. BAER MOTOR CONTROLLER Filed March 1925 I NVEN TOR.

a Ila ATTORNEY Patented May 29, 1928.

UNITED- STATES wan'rna'o. BAER, or mnwauxnnwrsoonsm, ASSIGNOR 'ro THEemanuse. 00., or mrnwauxna, Wisconsin, 5 conronm wmqoxsm PATENT OFFICE.

no'ron comnoma Application filed mm 5, 1925. Serial at. 13,001.

high voltage running connections for the motor armature and a switch forconnecting the field of the motor-to a .direct current source. Inpractice it has been found that the design of the motor andcertainother.

conditions renders it necessary in some instances to effect closure ofthe running switch prior to closure of the field switch, and, in otherinstances, to effect closure of such switches in reversed sequence.

They present invention has among its objects to provide a controller forsynchronous motors including the above-mentioned switches, and means forvarying the sequence of closure of the running switch and thefieldcontrol switch.

Another object is to. provide a controller of the aforesaid characterincluding a timing relay having contacts associated therewith which areadjustable to vary the sequence of closure .of the running switch andthe field control switch.

Various other objects and advantages of the invention will hereinafterappear.

The accompanying drawing illustrates an embodiment of the inventionwhich will now be described, it being understood that the embodimentillustrated is susceptible of modification without departing fromthespirit and scope of the appended claims.

In the drawing:

Figure 1 dia rammatically illustrates a controller embo ying theinvention, and

Fig. 2'is a so-called across-the-lin'e diagram of the circuitconnections of the con-" troller. shown in Fig. 1.

Referring to Fig. 1, the same illustrates a synchronous motor M havingan armature A to be supplied with current from a threephase alternatingcurrent circuit indicated by lines L, L and L, and a field F to besupplied with current from a suitable direct current source, as, forexample, a battery B. As hereinafter set forth, the motor is adapted tobe brought up to speed and thereafter connected to its load by asuitable electroma etic clutch, the operating winding of sai clutchbeing indicated by reference character G.

The controller for motor M includes a pair of double poleelectromagnetic starting switches 1 and 2 for connecting the armature Ato lines L L and L through the med um of low voltage taps on compensatorwindings 3 and 4, and a double pole electromagnetic running switch 5 forconnecting said armature directly to lines L, L and Li. The field F ofthe niotor is controlled by an electromagnetic switch 6, such switchhaving normally open contacts 6 and (3 for connecting the field F acrossthe terminals of battery B, and a normally closed contact 6 for shuntina resistance R across the terminals of fiel F. The op erating winding 0of the aforementioned clutch is controlled by a device 7, having anoperating winding 7. Device 7 is retarded during response by adash pot7" and 78 the same is provided with normally open contacts 7, 7, 7 and7. Contact 7 serves to connect the clutch winding C across the terminalsof battery B through a resistance R, and contacts 7", 7 and 7 thereafteract progress vely to exclude said resistance from the circuit of saidwinding in steps.

The control means for the aforementioned switches includes relays 8, 9,10 andll. Relay 8 is royided with an operating winding 8 and ur n returnmovement thereof to normal position the-same is retarded bya dash pot8*. Relay 8 is further provided with normally 'closed contacts- 8 and 8Eand a normally open contact .8". For a purpose hereinafter set forthcontacts 8 and 8' are ad ustable to provide for closure of contact 8prior to openin of contact 8 or for closure of contact 8 ollowing o ningof con-- tact 8. Belay 9 is provide with an operating winding 9 and theenergizing circuit thereof is controlled bya normally open push button:12 and a normally closed ush button 13. As hereinafter set forth re ay9 15 provided with a'normally open auxiliary contact 9 for establishinga maintaining circuit therefor through push button 13. 7 Relay 10 isprovided with an operating winding 10, a normally closed contact 10* andfollowing auxiliar .switch 1 is provide with a normally open 'cuitconnections thereo fully set forth in connection with. Fig. 2.

normally open contacts 10 and 10", and rela' 11 is normally closed andis provided with an operating winding 11 to be includedin series withthe motor during starting thereof. y

The control means further includes the contacts. Starting auxiliarycontact 1", and starting switch 2 is providedwith a normally openauxiliary contact 2 and a normally closed auxiliary contact 2. Runningswitch 5 is provided with a normally closed auxiliary contact 5 and anormally open auxiliary contact 5, and field switch 6 is provided with anormally open auxiliary contact 6. The clutch control device 7 isprovided with a normal- 1y closed auxiliary contact 7 and. a normally enauxiliary conta'ct.7", said contacts belllg adapted as hereinafter setforth to include and exclude a resistance r in the energizing circuit ofwinding 7 The function and operation of theaforedescribed controller, toether with the cirwill now be more Upon depression of push button 12rela 9 is energized by'a circuit extending from ine L through said pushbutton, through push button 13 and the operating winding 9 of said relayto line L. In res ending, relay 9 maintains itself through a circuitextending from line L through the auxiliary contact 9" thereof and thenormally closed ush button 13 to line L. Upon closure 0 rela 9, relay 8is energized by a circuit exten ing fromoline L through relay 9, throughthe normally closed auxiliary contact associated with running switch 5,through the operatlng winding 8 of said relay and through the normallyclosed auxiliary contact of rela 10 toline L. Relay 8 in responding estalishes an energizing circuit for starting switch 2 extending from line Lthrough relay 9 and the auxiliary con tact 5 of switch 5 to and throughthe operating winding 2 of said starting switch and through theauxiliary contact 8-of relay 8 to line L. Upon response of startingswitch 2, starting swltch 1 is energized by a circuit extending fromline L throu h relay 9 to and through the operating win ing 1 of saidstarting switch and through auxlliary contact 2" of starting switch 2 toline L. -.As shown in Fig. 2, one terminal of the armature winding 'ispermanently connected to line L and upon response of switches 1 and 2compensator windings 3 and 4 are connected between lines L1 L2 and L? f,respectively, while the other terminals of said armature winding areconnected to low volt age taps on said compensator windings. The motorthen starts with the field winding thereof connected in shunt acrossresistance R by contact 6 of field switch 8. It will be. observed fromFig. 2 that during starting of the motor the operating winding 11 ofseries relay 11 is connected in series between the'low voltage tap oftransformer 3 and one terminal of the armature winding. Re lay 11responds upon the initial inrush of current, but upon a given increasein the speed of the motor the same returns to normal position. Uponreturn of relay 11 to .normal position relaylO is energized by a throughopening of contacts-10". Upon return of relay 8 to normal position,running switch 5 and also the fieldswitch 6 are energized. Theenergizing circuit for running switch 5 extends from line L throughrelay 9, through the operating winding 5 of said switch, throughauxiliary contact 2 of starting switch 2 and contacts 10 of relay 10 toline L. The energizing circuit for field switch 6 then extends from lineL through switch 9 andwinding 6 of said field switch and through contact10 of relay 10 and contact 8 of relay 8 to line L. Upon response ofrunning switch 5, the motor armature is connected directly to lines L, Land L and upon response of field switch 6. the field of the motor isconnected across the terminals of battery B, through contacts 6 and 6;Following establishment of the aforedescribed running connections forthe motor, the clutch control device 7 is energized by a circuitextending from the left hand terminal of battery B through auxiliarycontacts 7 through the operatingwinding of said clutch control device,contact 7 opens and contact 7 closes to include a protective re sistancer in the energizing circuit of winding 7. I

As before stated, due to the design of the motor and other conditions,it is necessary in some instances to -efi'ect'closure of the runningswitchprior to closure of the field switch, and in other instances, toreverse the sequence 0 operation'of such switches.

will reverse the sequenceof' operation of To provide for variation ofsuch switches. the sequence of closure of running switch 5 and fieldswitch 6, contacts 8 and 8 are slidably mounted upon the operatingmember of relay 8, and the same have associated stops 16 and 17respectively. Stops 16 and 17 are threaded upon the operating member 15and contacts 8 and 8 are biased towards their respective stops bysprings 18 and 19, respectively. It is apparent that'by-properadjustment of the stops 15 and 16 the sequence of operation of switches5 and 6 can be varied as desired.

In practice it is desirable to energize the clutch winding C only afterclosure of running switch 5 and field switch 6. For this purpose,contact 8 of relay 8 is arranged to close after closure of contact 8and'opening of contact 8 What I claim as new by LettersPatent is:

.1. The combination with a synchronous motor, of switches forselectivelyestablishing reduced voltage armature connections for starting and fullvoltagearmature connections for running, aswitch for connecting thefield of the motor to a source of direct current, and control means forthe aforesaid switdies including means for timing the operation thereof,said latter means includ ing means for varying the sequence of clo sureof said field control switch and said running switch.

2. The combination with a synchronous motor of electro-responsiveswitches for selectively establishing reduced voltage and desire tosecure armature connections-for starting and full volt-age armatureconnections for running, an electro-responslve switch for connectlng thefield of the motor to a source of direct current and control means forthe aforesaid switches including an electro-responsive relay for timingthe operation thereof, said relay having contacts which are adjustableto vary the sequence of closure of said field control switch and saidrunning switch.

3. The combination vwith a synchronous motor of electro-responsiveswitches for establishing reduced voltage armature eonnections forstarting and full voltage armature connections for runnin anelectro-responsive switch for connecting the motor field to a source ofdirect current and control means for the aforesaid switches including arelay subjected to control by current conditions in the motor circuitduring starting of'the motor, said relay includingcontacts which are.adjustable to vary the sequence of closure of said field control switchand said running switch.

.4. The combination with a synchronous motor of electro-responsiveswitches for selectively establishing reduced voltage armatureconnections for starting and high voltage armature connections forrunning, an electro-responsive switch for connecting the motor field toa source of direct current,

a relay subjected to control by current in the motor circuit duringstarting, said relay including means to control the'energizing circuitsof the aforesaid switches and being adjustable to provide for variationof the sequence of closure of said running switch and said field controlswitch.

5. The combination with a synchronous motor of electro-responsiveswitches for establishing reduced voltage armature connections forstarting, an electro-responsive switch for establishing high voltagearmature connections for running, an electro-responsive switch forconnecting the motor field to a source of direct current, and controlmeans for the aforesaid switches including a relay for timing theoperation thereof, said relay being responsive to effect closure of saidstarting switches, and returning to normal position under given currentconditions inthe motor circuit to effect opening of said starting switchand closure of said running switch and said field control switch, andmeans associated with said relay for varying the sequence of olesure ofsaid running switch and said field control switch. I

6. The combination with a synchronous motor of electro-responsiveswitches for establishing reduced voltage armature'connections forstarting, an elec'tro-responsive switch for establishing high voltagearmature connections for running, an electro-responsive switch forconnecting the motor field to a source of direct current, and controlmeans for the aforesaid switches including a relay for timing theoperation thereof, said relay being responsive toefi'ect closure of saidstarting switches and returning to normal position under given currentconditionsin the motor circuit to elfect opening of said starting switchand closure of said running switch and said field control switch, saidrelay being also adjustable to Vary the sequence of closure of saidrunning switch and WALTER o. BAER.

